A study of platelet specific antibody (anti-Sib(a))

To screen and analyse the platelet-specific alloantibody form the sera of patients who received multiple platelet transfusions or experienced side effects after platelet transfusions.

156 patients, who received multiple platelet transfusion or experienced side effects after platelet transfusion, were collected from hospitals in Shanghai. The simplified sensitized erythrocyte platelet serology assay (SEPSA) was used to screen the platelet antibodies and the identification of specificities of the platelet alloantibodies was performed with a platelet panel of known antigens and absorption tests.

Seventy-four sera were found positive. Among them 59 sera (47.4%) contained HLA antibodies, two sera (2.7%) platelet-specific antibodies, and 13 sera both HLA and platelet-specific antibodies. One of 2 sera containing platelet-specific alloantibody, the serum Zhu, was confirmed to have a monospecific platelet-specific alloantibody, the anti-Sib(a) (HPA-2b).

We report the first case of anti-Sib(a) in Chinese Han population. The antigen frequency of Sib(a) is considered as one of the most important antibodies which will cause the platelet transfusion refractoriness in China.